Black Holes Aren't Always Super-Sized, Medium Discovered

Experts have been fairly certain for a long time that there are two sizes for black holes, small and incredibly colossal. Now however, researchers claim to have identified medium-sized black holes, a potential phenomenon that has long been shrouded in confusion and doubt.

"Objects in this range are the least expected of all black holes," astronomy researcher Richard Mushotzky from the University of Maryland said in a statement. "Astronomers have been asking, do these objects exist or do they not exist? What are their properties? Until now we have not had the data to answer these questions."

According to a study recently authored by Mushotzky and published in the journal Nature, an intermediate-sized black hole can be up to 10,000 times the mass of the Sun. That's significantly smaller than the supermassive black holes that inhabit the center of galaxies, which traditionally are more than one million time's the Sun's mass.

Medium black holes are also much larger than other non-supermassive black holes previously observed in the Universe, which range from 10 to 100 times the mass of the Sun.

Even as far back as several decades ago, astronomers identified what they suspected were intermediate black holes. However, according to Mushotzky, "for reasons that are very hard to understand these objects have resisted standard measurement techniques."

In an attempt to get the first conclusive readings of an intermediate black hole, Mushotzsky and his colleagues turned their attention to the starburst galaxy - where young stars are still forming - closest to Earth, M82. There, past observations have identified an object known as M82 X-1 that had long been suspected to be a medium-sized black hole.

The researchers reportedly analyzed over 800 observations made by the Rossi X-ray Timing Explorer (RXTE), which recorded individual x-ray particles emitted by M82 X-1.

These emissions showed a rhythmic pattern of light pulses, one occurring 5.1 times per second and the other 3.3 times per second - a ratio of 3:2. Those pulses told researchers the specific oscillations of materials circling the black hole, in turn indicating that M82 X-1 is about 428 times the mass of the Sun - making it the first truly measured intermediate black hole.